Tuning Electronic Properties of Monolayer Molybdenum Disulfide*

Molybdenum disulfide (MoS₂) has emerged as a prototypical material among the 2D transition metal dichalcogenides for its stability, low cost and unique electronic, optical and mechanical properties. Its electronic properties can be tuned using different control parameters. This great sensitivity presents an opportunity to functionalize its properties through defect engineering, strain or by proximity to another material. We use high resolution low temperature STM/STS to study the local electronic properties of monolayer MoS₂. We were able to induce strains up to 3% before slipping effects take place and relaxation mechanisms prevail. We found a reduction of the quasiparticle bandgap of about 400 meV per percent local strain with a minimum gap of 1.2 eV. Heterostructures based on MoS₂ offer another viable possibility to tune its electronic properties. In this case, interactions between the planes of different materials are expected to modify the electronic properties of the constituent materials and open unprecedented possibilities of combining them for technological use.